Method and apparatus for wrapping pipe



1955 P. F. MARX ETAL METHOD AND APPARATUS FOR WRAPPING PIPE Filed Jan. 14, 1953 IN VEN TOR.

NIETHOD APPARATUS 'FOR WRAPPING PIPE Paul F. Marx and Le Roy L. Dressler, Bradford, 'Pa., assignors to Dresser Industries, .'Iuc., Dallas, Tex., a corporation of Pennsylvania Application January 1.4, 1953,-Seri al No. 331,272

9 Claims. (Cl. 154-41) The present invention relates-to amethod and apparatus for applying pressure-sensitive tape to cylindrical or other objects. The method and apparatus in accordance with the invention are particularly suitable and useful for applying tape to pipe. In order to simplify the following description and claims, reference is made to wrapping pipe with pressure-sensitive-tape but it will be understood that the invention is not limited to the wrapping of pipe .andthat the term pipe is herein used in anillustrative .rather thana restrictivesense.

It has been .found advantageous .to -.wrap .pipe with pressure-sensitive tape, ,for. example .-to .protect the .pipe against corrosion. Tape suitable for such usecomprises a strip, band or ribbonof flexible material, for example fabric, plastic orpaper .coatedonone side with a tacky adhesive having the characteristic of adhering to a dry surface when pressed againstdt withoutthe needof applying any wetting agent or .solventto the tape. Such tape is .availableon the -mar-ket .nnder the trade name Dressertape. The tape iscustomarily supplied inaroll wound on a core having an axial bore orholeand may be of various sizes. For example, tape suitable for wrapping pipe may be purchased in arollaboutfour inches ,long (this being the width ofthe tape) .andabout six and onehalfinches outsidediarneter, with an axial hole about one and one-quarter inches in diameter.

Inwrapping pipe-byhand with pressure-sensitive tape, ditliculty is experienced in applying the tape to the;pipe smoothly and uniformly with predetermined overlap of successive convolutions of the tape. If the tape wrinkles when being wrapped oil-the pipe, the wrinkles-mayprovide n inute channels or passageways through which moisture can reach the pipe to cause-corrosion. The maintenance of uniform overlapisalsohighly important. It' the overlap is insufiicient, thepipe, is notproperly protected. lithe overlap is excessive,.it results in'a waste of'the tape which is relatively expensive.

Difficulty is also experienced in wrapping pipe outdoors in cold weather. When the temperature is low, the tape will not adhere properly to the cold pipe. While adhesion can, in some instances, be irnproved'by preheating the pipe, thisis not ordinarily practicable, particularly if the pipe is already in service.

It is an object of the present invention to'provide an improved method and apparatusfor Wrapping objectsherein referred to as pipefwithrpressurersensitive tape so as to insure that the tape goes on smoothly and uniformly with predetermined overlap. .A further object of the invention is to facilitate the'wrapping of pipe with pressure-sensitive tape in .cold weather and to assure proper adhesion of the tape to the pipe without the need of preheau'ng the pipe.

Other objects and advantages of theinvention will be apparent from the following description and-claims and from the accompanying drawings whichillustrate, by way of example, a preferred embodiment of the invention.

ln-the drawings:

Fig. 1, is :a perspective --viewof apparatus for applying United States Patent G rah 2 pressure-sensitive adhesive tape to pipe, in accordance with the invention, certain interior portions being shown in dotted lines.

Fig. 2 is a cross section taken approximately onthe line 2-2 in Fig. l, the roll of tape being shown in dotted lines to avoid obscuring portions of the apparatus.

The apparatus illustrated by way of example in the drawings comprises an enclosure 1 shown in the form of a prismatic case or box of approximately square cross section. The enclosure 1 has opposite end walls 2, side Walls 3 and 4, bottom 5 and top or cover 6. The enclosure is preferably formed from strong, heat-insulating material, for example plywood, cardboard, fiber board, pressed wood or plastic. The end walls ,2 are shownapproximately square and have central apertures ,8, the

apertures of the opposite ends being in alignment With one another. The cover 6 is arranged so that it can be removed or opened. For example, itis hingedly attached to one of the end walls by means of hinges 9, a catch 10 being provided at the opposite endof the cover to hold the cover in closed position. One of the .side walls 4 is provided with an elongated slot 12 having alengthgrcater than the width of the tape that'is to beapplied. Inthe construction shown in the drawings, the slot .12 isformed by recessing a portion of the upper edge oftheside wall 4, the upper edge of the slot being formed by an edge 13 of the cover 6 that is spaced from the recessed portion of the upper edge of the side wall 4.

The enclosure 1 is large enough to .receive arollof pressure-sensitive adhesive tape T, the roll being shown in dotted lines in Figs. 1 and 2 and indicated by the reference numeral 15. The roll has an axial bore or hole 16 and is disposed in the enclosure so that the axial hereof the roll is aligned with the apertures 8 in the opposite end walls 2. A shaft 18 is inserted through the apertures 3 in the end walls 2 of the enclosure 1 and through-the axial hole 15 of the roll 15. The shaft is longer than; the enclosure 1 so that the end portions of the shafuproject out beyond the end Walls 2. The diameter of the shaft is somewhat less than that of the apertures 8 and the hole 15, so that the shaft is rotatable and movable axially relative to the enclosure 1 andthe roll of tape 15. Spacing sleeves 20 surround the shaft 18 and are disposed, respectively, between the opposite ends o'fthe -roll of tape 15 and the end walls 2 of the enclosure .1 so as to position the roll and keep it approximately-centered hetweenthe end walls. It will be seen that the roll of tape 15 is rotatably supported in the enclosure 1 by the shaft -18 and is positioned in an axial direction by the spacing sleeves 29 so that the ends of the roll arespaced from the end walls 2 of the enclosure.

The slotted side wall 4 of the enclosurel is adapted to engage the pipe during applicationof the tape, as described more fully below. To prevent its being abraded by the pipe, the side wall 4 is at leastpartiallycovered by a wear plate 22 made of abrasion-resistant material, for example metal. While the wear plate 22 may, if desired, cover the entire side wall 4-except.for the slot 12-it ordinarily sufiices-for it to cover only a central zone extending the length of the side wall, as illustrated in Figs. 1 and 2. The drawings also illustrate the provision of rollers 23 adapted to engage thepipe. The rollers 23 are shown arranged inpairs, with one pair disposed near one endof the enclosure ,1 and the other pair disposed near the opposite end of the enclosure. The two rollers of each pair are spaced laterally from one another. The rollers 23 are rotatably mounted on the side wall 4, for example bymeans of pins 24 extending between spaced ears or lugs 25 bent up from the wear plate 22. The axes of the rollers 23 arepreferably parallel to one another and disposed at a slight angle to a plane passing through the axis of'the shaft pipe.

7 3 I 18 and midway between the rollers of each pair, i. e. a horizontal plane passing through the axis'of the shaft '18, as illustrated in Fig. 2. While the slotted sidewall '23 may be omitted.

It has been found that, if the pressure-sensitive adhesive tape is kept warm, it can satisfactorily be applied to pipe in cold weather and will adhere properly to the pipe, even though the pipe itself is cold. In order to keep the tape warm, one or more heaters are provided in the heat-insulated enclosure 1. The heater or heaters are properly disposed to apply a suitable amount of heat to the tape. In the embodiment illustrated in the drawings, there are two heaters 30 disposed at opposite ends of the enclosure. The heaters are selected to provide a predetermined amount of heat over a substantial period of time, for example several hours. Suitable heaters for this purpose are pyrophoric or catalytic heaters using hydrocarbon fuels such as benzine or white gasoline. A flameless catalytic heater of the pocket hand warmer type has been found satisfactory for this purpose. Each heater has a metal case with a plurality of openings 31 for admitting air to the heater. Suitable openings 32 corresponding approximately in position to the holes 31 of the heater case are provided in the end Walls 2 of the enclosure 1. Means is provided for releasably holding the heaters'30 in position in the enclosure 1. As shown in the drawings, the holding means for each heater comprises a small spiral spring 33 fastened at its ends to the enclosure wall, for example by small screw eyes 34.

The steps in applying pressure-sensitive adhesive tape to pipe in accordance with the invention are as follows. A roll of tape is positioned in the enclosure 1, as described above, and an end portion of the tape T is brought out through the slot 12 in the side wall 4. I he shaft 18 is inserted through the openings 8 in the end walls of the enclosure and the axial hole 16 in the roll of tape with spacing sleeves 20 maintaining the roll in proper axial position. The heaters 30 are ignited or otherwise started and placed in the holders 33. The end portion of the tape is adhesively atfixed to the pipe. The operator then grasps the projecting end portions of the shaft 18 and, using these portions as handles, moves the enclosure 1 with the tape contained therein round and round the The axis of the shaft 18 is kept approximately parallel to the axis of the pipe. As the shaft 18 is carried around the pipe, the roll of tape can turn around the axis of the shaft as the tape is unrolled. The slotted side wall 4 of the enclosure is held in contact with the pipe as the shaft 18 is carried around the pipe, the enclosure being rotatable on the shaft so that the side wall 4 remains approximately tangential to thepipe. Abrasion of the side wall 4 by the pipe-which may be rough-is prevented by the wear plate 22. When the side wall 4 is provided with rollers 23, the rollers roll around the pipe as the tape is wrapped on. By positioning the rollers 23 at an angle, as described above, the

enclosure 1 containing the tape is caused to move axially along the pipe as it travels around the pipe, the amount of axial travel or lead being chosen so as to provide predetermined overlap of successive convolutions of the tape. The amount of overlap can also be accurately controlled by providing one or more indices on the enclosure 1, such as peripherally extending lines 35, 36 and 37 (Fig. 1.) By maintaining one or another of the indices 35, 36 or 37 at the edge of the preceding convolution of tape, the amount of overlap of the tape is accurately regulated. If the central index 36 is used, the tape will overlap by half its width. Greater or lesser amount of overlap is obtained by using other of the indices. While enclosure 1, his movable axially relative to the enclosure so as to permit the enclosure to be brought up close to an obstacle when, for example, it is desired to Wrap a portion of pipe near a wall, bulkhead, flange, or other obstruction. I

In cold weather, the heaters 30 maintain the tape in a predetermined temperature range, so that it will adhere securely to the pipe, even though the pipe itself is cold. When using Dressertape, it is desirable to maintain the temperature of the tape in the range between 75 F. and F. a

It has been found that, with an outside temperature below freezing, for example around 28 F., the temperature in the enclosure can be maintained at 75 F., to 80 F., by the use of two pocket hand warmers, as illustrated and described.

It will be understood that the invention is not limited to the apparatus shown by way of example in the drawings. Moreover, terms defining the relation of the several parts, for example parallel, are used in a general descriptive sense rather than in an exact sense and are intended to cover arrangements that are substantially or approximately as described. Various modifications with in the scope of the appended claims will be apparent to those skilled in the art.

What we claim and desire to secure by Letters Patent is:

1. In apparatus for applying pressure-sensitive adhesive tape to pipe, said tape being supplied in a roll with an axial hole, an enclosure having opposite end walls with aligned central apertures and a side wall having an elongated slot parallel to the axis of said apertures, said'enclosure being sufiiciently large to receive said roll with the axial hole of. the roll aligned with said apertures and said slot being longer than the width of said tape, a heater in said enclosure, means for releasably holding saidheater able relative to said roll and enclosure, the end of said a tape being led out through said slot and the tape being wrapped on the pipe by carrying said shaft, with the roll and enclosure thereon, around the pipe while maintaining the shaft approximately parallel to the axis of the pipe and the slotted side of the container in contact with the pipe, the roll and enclosure rotating on said shaft as it is carried around the pipe.

2. In apparatus for applying pressure-sensitive adhesive tape to pipe, said tape being supplied in a roll with an axial hole, an enclosure having opposite end walls with aligned central apertures, a side wall having an elongated slot parallel to the axis of said apertures and an openable cover, said enclosure being sufiiciently large to receive said roll with the axial hole of the roll aligned with said apertures and said slot being longer than the width of said tape, a catalytic heaterv in said enclosure, means for holding said heater in position in said enclosure, the wall.

of said enclosure having openings therein to supply air for said heater, and a shaft extending through said apertures and hole, said shaft beinglonger than said enclosure and being rotatable and axially movable relative to saidroll and enclosure, the end of said tape being led out through said slot and the tape being wrapped on the pipe and enclosure rotating on said shaft as it is carried around.

the pipe.

a 3. Apparatus according to claim 2, having two'heaters positioned respectively adjacent opposite end walls of the enclosure.

4. In apparatus for applying pressure-sensitive adhesive tape to pipe, said tape being supplied in a roll with an axial hole, an enclosure having opposite end walls with aligned central apertures and aside wall having an elonthe shaft 13 normally projects from both ends of the gated slot parallel to the axis of said apertures, said enclosure being sufiiciently large to receive said roll with the axial hole of the roll aligned with said apertures and said slot being longer than the width of said tape, a shaft extending through said apertures and hole, said shaft being sufficiently longer than said enclosure to project and provide handholds at both ends of said enclosure and being rotatable and axially movable relative to said roll enclosure, and spacing sleeves surrounding said shaft and disposed between the ends of said roll and the end Walls of said enclosure to retain said roll in predetermined position relative to said end walls, the end of said tape being led out through said slot and the tape being wrapped on the pipe by carrying said shaft, with the roll and enclosure thereon, around the pipe while maintaining the shaft approximately parallel to the axis of the pipe and means on the enclosure engaging the pipe and assisting in guiding the enclosure in its movement around the pipe, the roll and enclosure rotating on said shaft as it is carried around the pipe.

5. In apparatus for applying pressure-sensitive adhesive tape to pipe, said tape being supplied in the form of a roll with an axial hole, a box formed with walls of heatinsulating material, said box having opposite end walls with aligned central apertures and a side wall having an elongated slot parallel to the axis of said apertures, said box being sufliciently large to receive said roll with the axial hole of the roll aligned with said apertures and said slot being longer than the width of said tape, a wear plate of abrasion-resistant material at least partially covering the slotted side of the box, a shaft extending through said apertures and hole, said shaft being longer than said box and being rotatable and axially movable relative to said box, the end of said tape being brought out through said slot and the tape being wrapped on the pipe by moving said shaft, with the roll and box supported thereon, helically around the pipe while maintaining the shaft approximately parallel to the axis of the pipe and the wear plate on the slotted side of the box in contact with the pipe, the box rotating on said shaft as it is carried around the pipe.

6. In apparatus for applying pressure-sensitive adhesive tape to pipe, said tape being supplied in the form of a roll with an axial hole, an enclosure having opposite end walls with aligned central apertures and a side wall having an elongated slot parallel to the axis of said apertures, said enclosure being sufliciently large to receive said roll with the axial hole of the roll aligned with said apertures and said slot being longer than the width of said tape, spaced pairs of rollers on the slotted side of said enclosure, the rollers of each pair being spaced laterally from one another and the pairs being spaced axially from one another, and a shaft extending through said apertures and hole, said shaft being longer than said enclosure and being rotatable and axially movable relative to said enclosure, the end of said tape being brought out through said slot and adhesively aflixed to the pipe and the tape being thereupon wrapped on the pipe by moving said shaft, with the roll and enclosure supported thereon, in a helical path around the pipe while maintaining the shaft approximately parallel to the axis of the pipe, and the rollers in contact with the pipe, the enclosure rotating on said shaft as it is carried around the pipe.

7. Apparatus according to claim 6, in which said rollers are rotatable about axes that are parallel to one another and are inclined relative to a plane passing through the axis of said apertures and midway between the rollers of each pair, so that the enclosure is moved axially along the pipe with a predetermined lead as it is carried around the pipe.

8. in apparatus for applying pressure-sensitive adhesive tape to pipe, said tape being supplied in the form of a roll with an axial hole, an enclosure having opposite end walls with aligned central apertures, a side Wall having an elongated recessed portion in its upper edge extending substantially the full length of said edge and an openable cover having an edge portion spaced from the recess edge portion of said side wall to provide an elongated slot parallel to the axis of said apertures, said enclosure being sufliciently large to receive said roll with the axial hole of the roll aligned with said apertures and said slot being longer than the width of said tape, and a shaft extending through said apertures and hole, said shaft being sufficiently longer than said enclosure to project and provide handholds at both ends of said enclosure and being rotatable and axially movable relative to said enclosure, the end of the tape being brought out through said slot and adhesively aflixed to the pipe and the tape being wrapped on the pipe by carrying said shaft, with the roll and enclosure thereon, around the pipe while maintaining the shaft approximately parallel to the axis of the pipe and means on the enclosure engaging the pipe and assisting in guiding the enclosure in its movement around the pipe, the enclosure rotating on said shaft as it is carried around the pipe.

9. In apparatus for applying pressure-sensitive adhesive tape to pipe, said tape being supplied in the form of a roll with an axial hole, an enclosure having opposite end walls with aligned central apertures and a side wall having an elongated slot parallel to the axis of said apertures, said enclosure being sufliciently large to receive said roll with the axial hole of the roll aligned with said apertures and said slot being longer than the width of said tape, and a shaft extending through said apertures and hole, said shaft being sufliciently longer than said enclosure to project and provide handholds at both ends of said enclosure and being rotatable and axially movable relative to said enclosure, the end of said tape being brought out through said slot and adhesively aflixed to the pipe, and the tape being thereupon wrapped on the pipe by moving said shaft, with the roll and enclosure supported thereon, around the pipe while maintaining the shaft approximately parallel to the axis of the pipe, means on the enclosure engaging the pipe and assisting in guiding the enclosure in its movement around the pipe and an index on the enclosure cooperating with an edge of the tape wound on the pipe to serve as a guide for moving the enclosure in a direction axial of the pipe as it is moved around the pipe to provide a predetermined overlap of successive convolutions of the tape on the pipe.

References Cited in the file of this patent UNITED STATES PATENTS 1,226,928 Updike May 22, 1917 1,379,756 Friend May 31, 1921 1,799,59 Moore Apr. 7, 1931 

